Method and device for performing beam refinement in wireless communication system

Abstract

A method for a terminal performing beam refinement in an mmWave communication system can be provided according to an embodiment of the present description. A method for a terminal performing beam refinement can comprise the steps of: transmitting a RACH preamble to a base station; receiving a RACH response from the base station; transmitting an RRC connection request message to the base station; and receiving a response message to the RRC connection request message. If beam inconsistency occurs in the terminal, ID information of a pre-connected terminal can be comprised in a terminal ID field of the RRC connection request message.

What is claimed is: 
     
       1. A method for performing beam refinement by a User Equipment (UE) in an mmWave communication system, the method comprising:
 transmitting, to a base station (BS), a Random Access CHannel (RACH) preamble; 
 receiving, from the BS, an RACH response; 
 transmitting, to the BS, an RRC connection request message including at least one of a Channel State Information-Reference Signal (CSI-RS) request field and Channel State Information (CSI); and 
 receiving, from the BS, a response message in response to the RRC connection request message based on a detection of a beam mismatch, 
 wherein, when the beam mismatch is detected, ID information of the UE is included in a UE ID field of the RRC connection request message, 
 wherein, based on the CSI-RS request field set to a first value, information on a CSI-RS is received through at least one of Downlink Control Information (DCI) and Medium Access Control-Control Element (MAC-CE), 
 wherein at least one of a CSI-RS process reuse field, a CSI-RS resource allocation field, and a CSI-RS process selection field is received together with the information on the CSI-RS, and 
 wherein, based on the CSI-RS process reuse field set to a first value, scheduling information on CSI-RS process configuration is received together with the information on the CSI-RS. 
 
     
     
       2. The method of  claim 1 ,
 wherein, when the beam mismatch is detected, the response message includes beam change indication information. 
 
     
     
       3. The method of  claim 1 ,
 wherein the CSI-RS resource allocation field indicates time and frequency resource information for transmitting the CSI-RS and the CSI process selection field indicates a process used for transmitting the CSI-RS. 
 
     
     
       4. The method of  claim 1 ,
 wherein the CSI information is Beam State Information (BSI) and the CSI-RS is a Beam Refinement Reference Signal (BRRS). 
 
     
     
       5. The method of  claim 4 ,
 wherein the CSI-RS request field is a BRRS request field, the CSI-RS process reuse filed is a BRRS process reuse field, the CSI-RS resource allocation field is a BRRS resource allocation field, the CSI-RS process selection field is a BRRS process selection field, and the CSI-RS process configuration is BRRS process configuration. 
 
     
     
       6. A user equipment (UE) for performing beam refinement in an mmWave communication system, the UE comprising:
 a receiver for receiving a signal; 
 a transmitter for transmitting; and 
 a processor configured to control the receiver and the transmitter, 
 wherein the processor is further configured to:
 transmit, to a base station (BS), a Random Access CHannel (RACH) preamble; 
 receive, from the BS, an RACH response; 
 transmit, to the BS, an RRC connection request message including at least one of a Channel State Information-Reference Signal (CSI-RS) request field and Channel State Information (CSI); and 
 receive, from the BS, a response message in response to the RRC connection request message based on a detection of a beam mismatch, 
 
 wherein, when the beam mismatch is detected, ID information of the UE is included in a UE ID field of the RRC connection request message, 
 wherein, based on the CSI-RS request field set to a first value, information on a CSI-RS is received through at least one of Downlink Control Information (DCI) and Medium Access Control-Control Element (MAC-CE), 
 wherein at least one of a CSI-RS process reuse field, a CSI-RS resource allocation field, and a CSI-RS process selection field is received together with the information on the CSI-RS, and 
 wherein, based on the CSI-RS process reuse field set to a first value, scheduling information on CSI-RS process configuration is received together with the information on the CSI-RS. 
 
     
     
       7. The user equipment of  claim 6 , wherein when the beam mismatch is detected, the response message includes beam change indication information. 
     
     
       8. The UE of  claim 6 ,
 wherein the CSI-RS resource allocation field indicates time and frequency resource information for transmitting the CSI-RS and the CSI process selection field indicates a process used for transmitting the CSI-RS. 
 
     
     
       9. The UE of  claim 6 ,
 wherein the CSI information is Beam State Information (BSI) and the CSI-RS is a Beam Refinement Reference Signal (BRRS). 
 
     
     
       10. The UE of  claim 9 ,
 wherein the CSI-RS request field is a BRRS request field, the CSI-RS process reuse filed is a BRRS process reuse field, the CSI-RS resource allocation field is a BRRS resource allocation field, the CSI-RS process selection field is a BRRS process selection field, and the CSI-RS process configuration is BRRS process configuration.